recalculating the number of subdivisions of a cylinders
Select one of the cross sections and separate it into a new object or inverse the selection and delete the rest of the object.





Use the Screw modifier to recreate your wheel with Steps set to 30. You might need to change the Axis depending on how your wheel is oriented. Also  check the Merge Vertices checkbox.





Click the Apply button to convert the wheel back to an editable mesh.